Quick answer
Stop the water at the source, make the area electrically safe, photograph the damage, and start drying within 24 to 48 hours. The EPA says mold generally will not grow if wet items dry in that window. Treat sewage or other contaminated water differently: stay out and use a professional. Drying and mold work belong to a restoration company.
Stop the water first
For a burst or leaking supply line, close the main shutoff valve. Portland Water Bureau adds that after a pipe bursts you should also turn off the water heater at its dedicated cold water inlet valve. Tacoma Water advises turning off power to the water heater if the home has lost water altogether, to protect the heater. If you cannot find or close the main, call a plumber or your water utility.
If the water is coming up from a drain or toilet, the main shutoff will not stop it. That is a sewer problem. Seattle Public Utilities says not to flush toilets or run water appliances, and not to try to stop sewage flowing from floor drains.
Electricity and gas come before cleanup
Water and electricity are the first danger. FEMA says not to touch electrical equipment that is wet or while you are standing in water, and to shut off electricity only if it is safe to do so. The CDC says that if wiring or equipment got wet, turn off the power at the main breaker or fuse box, and if reaching it means entering standing water, call an electrician. It also says never to switch power on or off or use electric tools while standing in water.
Gas is the other warning. The CDC says to leave immediately if you smell gas. Call 911 or the gas utility from outside. If a leak is near a gas water heater or furnace, do not try to deal with it yourself.
Work out what kind of water it is
The kind of water decides what is safe to do. Under the IICRC standards that a Northern Arizona University water damage guideline references, water is sorted into three categories. Category 1, clean water, comes from sources such as broken supply lines, sink overflows without contaminants, and appliance supply faults. Category 2, gray water, includes dishwasher or washing machine discharge, toilet overflows with urine but no feces, and sump pump failures. Category 3, black water, is grossly unsanitary and includes sewage, toilet backflows from beyond the trap, and rising river water.
Time matters too. The same guideline says clean water can degrade as it touches materials and as time passes, and gray water left untreated in a structure for more than 48 hours can become Category 3. The EPA draws a similar line. Its drying guidance applies to clean water damage only. For sewage or other contaminated water, the EPA says to consult an experienced professional and not to run fans until the water is confirmed clean.
Document before you clean up
Take photos and video of the water, the source of the leak, damaged walls and floors, and every affected item before moving anything. FEMA recommends photographing damage to the home and destroyed items, saving samples of carpet and similar materials, and calling your insurance agent to start a claim. The CDC says to photograph soaked items you plan to discard.
The Washington State Office of the Insurance Commissioner made a related point after the December 2025 floods: ask your insurer how to meet your policy's duties after a loss, including how to photograph damaged items before removing them, and make the property available for inspection as soon as reasonably possible, because mold can grow quickly. That statement was about flood claims, but the common sense carries over to a leak. Coverage depends on your policy, so ask your insurer what yours includes.
Start drying, and understand the 24 to 48 hour window
The EPA's guide to mold says to dry water-damaged areas and items within 24 to 48 hours, and that in most cases mold will not grow if wet items are dried in that window. The CDC gives the same time frame for cleaning and drying a home after water damage and says to fix plumbing leaks as soon as possible. The EPA also calls the 48 hour mark a guideline, not a hard cutoff. Mold can develop even when materials are dried within 48 hours, and it does not always develop after.
The CDC suggests opening doors and windows and using fans and dehumidifiers once electricity is safe. Stopping the leak and removing standing water are things you can start now. Structural drying with industrial equipment is the job of a water damage restoration company, not a plumber.
What usually has to come out
Some materials cannot be dried in time. The EPA's mold remediation guidance, written for schools and commercial buildings, says ceiling tiles and cellulose or fiberglass insulation that get wet should be discarded and replaced. Drywall may be dried in place if it is not swollen and its seams are intact, and otherwise should be removed. Carpet padding must be dried along with the carpet, or mold is likely. The CDC lists mattresses, carpeting, rugs, upholstered furniture, pillows and books among items to throw away if they cannot be cleaned and dried quickly.
Standards differ on timing. The Northern Arizona University guideline says drying of drywall should begin within 48 hours and be complete within 72, and that carpet should be replaced if Category 1 or 2 water sits for more than 48 hours or any Category 3 water touches it. The CDC says drywall and insulation contaminated with sewage or floodwater should be removed and discarded. A restoration company can assess which materials in your home meet those limits.
Fix the source, then dry for good
The EPA is direct about this: the key to mold control is moisture control. Cleaning up mold without fixing the water problem means it will likely return. That makes the plumbing repair part of the drying plan, not a separate task. Hidden leaks inside walls or under floors can keep materials wet long after the visible water is gone, so if surfaces will not stay dry, ask for leak detection.
The EPA says most people can clean small moldy areas of about 10 square feet themselves, while larger areas warrant its remediation guidance or a qualified contractor. The CDC recommends protective gear for mold cleanup, including goggles, an N-95 respirator and gloves.
When to call Pyper Plumbing
Call Pyper Plumbing to stop and repair the source of the water: a burst or leaking pipe, a failed fitting, a leaking water heater, or a sewer problem. Pyper provides emergency plumbing repair, leak detection and repair, water heater service and sewer line repair in Snohomish, Skagit, Whatcom and Island counties.
Pyper does not do water damage restoration, structural drying or mold remediation. Those need a restoration company, and your insurer may have preferred contacts. A common sequence is to have the plumber stop and fix the leak, then have the restoration company dry and assess the damage.
Common questions
How long do I have before mold grows after a leak?
The EPA and CDC both point to a 24 to 48 hour window for drying. The EPA says mold generally will not grow if wet items are dried within that time, but calls it a guideline, since mold can sometimes grow sooner or not at all.
Should I turn off the power after a plumbing leak?
If water reached wiring, outlets or equipment, the CDC says to turn off power at the main breaker or fuse box, and to call an electrician if you would have to stand in water to reach it. Never touch electrical equipment while standing in water.
Can I dry out sewage water damage myself?
The EPA says its drying guidance applies to clean water. For sewage or other contaminated water, it advises consulting an experienced professional and not using fans until the water is confirmed clean. Wear protective gear and keep children and pets out.
Does a plumber do the drying?
No. A plumber stops and repairs the source of the leak. Drying equipment, moisture mapping and mold work are done by water damage restoration companies. Pyper Plumbing handles the plumbing repair side.
Sources
Facts in this guide come from the following references. Local rules and manufacturer instructions can differ, so follow your utility and your equipment manual.
- What to do if water pipes freeze, leak or burst (Portland Water Bureau)
- Fix and prevent water leaks (Tacoma Water)
- Returning Home After the Flood (FEMA)
- Guidelines for Cleaning Safely After a Disaster (CDC)
- 8 Tips to Clean Mold (CDC)
- A Brief Guide to Mold, Moisture and Your Home (U.S. EPA)
- Mold remediation in schools and commercial buildings, course materials (U.S. EPA)
- Water Damage Guideline (Northern Arizona University)
- Kuderer issues letter to insurance companies on post-flood expectations (Washington Office of the Insurance Commissioner)
- Side Sewer Backups (Seattle Public Utilities)
This guide is general information, not a substitute for an on-site inspection. If you smell natural gas, leave the building and call 911 or your gas utility. Pyper does not perform gas line work.
